1. Field of the Invention
The present invention relates to an immersion exposure apparatus and immersion exposure method, and a device manufacturing method.
2. Description of Related Art
In exposure apparatuses used in the photolithography process, immersion exposure apparatuses as disclosed in Japanese Unexamined Patent Application, First Publication No. 2004-289126 (corresponding to U.S. Pat. No. 6,952,253) and Japanese Unexamined Patent Application, First Publication No. 2004-289128 (corresponding to U.S. Pat. No. 7,075,616) which expose a substrate via a liquid are known. In addition, multi stage type (twin stage type) exposure apparatuses as disclosed in Published Japanese Translation No. 2000-511704 of PCT International Publication (corresponding to U.S. Pat. No. 6,262,796), Japanese Unexamined Patent Application, First Publication No. 2000-323404 (corresponding to U.S. Pat. No. 7,116,401), Japanese Unexamined Patent Application, First Publication No. 2000-505958 (corresponding to U.S. Pat. No. 5,969,441), Published Japanese Translation No. 2001-513267 of PCT International Publication (corresponding to U.S. Pat. No. 6,208,407), Japanese Unexamined Patent Application, First Publication No. 2002-158168 (corresponding to U.S. Pat. No. 6,710,849), comprising a plurality of substrate stages which hold a substrate are known.
In an immersion exposure apparatus, for example, if all of the liquid is recovered each time a substrate stage is separated from the projection optical system, such as at the time of exchanging a substrate, there is a possibility that throughput of the exposure apparatus declines. Moreover, when all of the liquid is recovered and the light emitting surface of the projection optical system is changed from a wet state into a dry state, there is a possibility that vaporization of the liquid causes formation of adhesion marks (water marks) of the liquid on the light emitting surface of the projection optical system, and produces temperature change, thus deteriorating the exposure accuracy. Accordingly, desirably, the light emitting surface of the projection optical system is kept wet with liquid at all times.
In a multi-stage type exposure apparatus, as in the conventional way, in the case where there is an attempt to keep the light emitting surface of the projection optical system wet with a liquid at all times by holding a cap member (shutter member) so as to face the light emitting surface of the projection optical system, there is a possibility that an undesirable conditions exists where the cap member drops down, the liquid on the cap member leaks, or the like. Moreover, there is a possibility that the throughput of the exposure apparatus declines due to the operation for transferring the cap member to/from the substrate stage. Accordingly, a technique is desired in which the light emitting surface of the projection optical system is kept wet with a liquid at all times so that the substrate can be efficiently exposed even in a case where the immersion method is applied to a multi-stage type exposure apparatus.
A purpose of some aspects of the invention is to provide an immersion exposure apparatus, immersion exposure method, and a device manufacturing method in which the substrate can be efficiently exposed even in a case where the immersion method is applied to a multi-stage type exposure apparatus.